Employing pressure switches in sensing edges for doors is generally known. Such sensing edges generally include a sheath having several openings or chambers therein in fluid communication with each other, in order to transmit therebetween pressure changes in response to the application of external pressure to the sheath. The problem associated with such edges is that in order to construct several openings or chambers in fluid communication with each other, a plurality of different types and structures of foam must be used within the sheath to provide the proper sensitivity and path to communicate the pressure changes therebetween. Therefore, constructing and assembling door edges of this type is costly.
Other types of more conventional door edges include a pair of upper or lower, flexible, electrically conductive sheets (e.g., aluminum foil) positioned on the upper and lower sides of a bridge. Upon application of pressure to the sheath, the conductive sheets are deflected into electrically conductive engagement with each other to thereby function as a switch to actuate suitable control circuitry for controlling the door. Sensing edges with this type of construction may not be as sensitive as that contemplated by the present invention. For instance, before the control circuitry is actuated, the conductor sheets must travel the full distance therebetween in order to make electrical connection. Whereas, in the present invention, the control circuit may be actuated without forcing the control tube to deflect a significant amount, as will be apparent from the description hereinafter.